Impact of use of optical surface imaging on initial patient setup for stereotactic body radiotherapy treatments

Purpose To evaluate the effectiveness of surface image guidance (SG) for pre‐imaging setup of stereotactic body radiotherapy (SBRT) patients, and to investigate the impact of SG reference surface selection on this process. Methods and materials 284 SBRT fractions (SG‐SBRT = 113, non‐SG‐SBRT = 171) were retrospectively evaluated. Differences between initial (pre‐imaging) and treatment couch positions were extracted from the record‐and‐verify system and compared for the two groups. Rotational setup discrepancies were also computed. The utility of orthogonal kVs in reducing CBCT shifts in the SG‐SBRT/non‐SG‐SBRT groups was also calculated. Additionally, the number of CBCTs acquired for setup was recorded and the average for each cohort was compared. These data served to evaluate the effectiveness of surface imaging in pre‐imaging patient positioning and its potential impact on the necessity of including orthogonal kVs for setup. Since reference surface selection can affect SG setup, daily surface reproducibility was estimated by comparing camera‐acquired surface references (VRT surface) at each fraction to the external surface of the planning CT (DICOM surface) and to the VRT surface from the previous fraction. Results The reduction in all initial‐to‐treatment translation/rotation differences when using SG‐SBRT was statistically significant (Rank‐Sum test, α = 0.05). Orthogonal kV imaging kept CBCT shifts below reimaging thresholds in 19%/51% of fractions for SG‐SBRT/non‐SG‐SBRT cohorts. Differences in average number of CBCTs acquired were not statistically significant. The reference surface study found no statistically significant differences between the use of DICOM or VRT surfaces. Conclusions SG‐SBRT improved pre‐imaging treatment setup compared to in‐room laser localization alone. It decreased the necessity of orthogonal kV imaging prior to CBCT but did not affect the average number of CBCTs acquired for setup. The selection of reference surface did not have a significant impact on initial patient positioning

The perception of women engineers in the construction industry in Palestine

The industrial and occupational distribution of women is such that women are concentrated predominately in a few occupations, mostly in the service sector, such as banking, finance, insurance, public administration, hotel, and catering. Men and women are equal in their capabilities in almost every respect, provided that women are given the same opportunities as men for training, employment, and promotion. There is a lack of research studies on women in the construction industry; therefore this field needs special consideration. The purpose of the current study is to find out working conditions of the Palestinian women civil and architect engineers in the construction industry in the Gaza Strip, Palestine. In addition, it attempts to examine their career prospects and to understand problems experienced by these women throughout their academic years as well as in their careers. Discrimination against women is still

Safety climate in construction industry the case of Gaza strip

The construction industry plays an important role in the social and economic development in Palestine. Safety in the construction industry is considered a major issue in developed and developing countries. Palestine's construction suffers recently from poor safety and health conditions as safety rules do not exists and work hazards at the workplace are not perceived. The main objective of this paper is to investigate the perceptions of construction workers regarding safey climate and safety behavior work in Gaza Strip construction sites. It will also explore the relationship between personal characteristics of constuction workers and safety climate/safe work behavior. Furthermore, the relationship between safety climate and safe work behavior will be explored. The methodology adopted in this paper was based on comprehensive questionnaire targeting the construction workers. 300 questionnaires were distributed and 246 questionnaires were collected and then analyzed to achieve the research objectives. It was found that construction workers have positive attitude and perception towards safety climate and safe work behavior. There exist a positive relationship between safety climate and safe work behavior. There is an impact of experience, field of work, smoking habit, and job on safety climate. In contrast, the personal characteristics; marital status, direct employer, educational level, family members to support, skill levels have no influence on safety climate. There exist a relationship between personal characteristics age, experience, field of work, smoking habit, educational level, and job on the field safe work behavior. On the other hand no impact

Effects of Faulty Design Phase on School Buildings Maintenance in Gaza Strip

The aim of this paper is to identify and rank the design phase faults/errors affecting on the maintenance of the United Nations Relief and Works Agency (UNRWA)'s school’s buildings in Gaza Strip, and to propose recommendations for minimizing the future maintenance problem related to the school buildings at Gaza Strip. A survey was conducted to collect the required data were adopted in this study. This study reveals the important factors that leading to defects in the design stage which includes: lack of workshops to discuss construction problems between project parts, Inadequate QA/QC programs during design stage, Lack of auditing and archiving of approved as-built drawing documents electronically after the completion the project. The study recommends several actions to improve maintenance performance of UNRWA's schools in Gaza Strip. The designer must take into account maintenance considerations during the design and supervision stages by choosing of durable materials. The UNRWA should conduct workshops or training courses for designers, supervisor, and maintenance engineers

Solid State Proton Spin Relaxation and Methyl and \u3ci\u3et\u3c/i\u3e-Butyl Reorientation

We have measured the temperature T and Larmor frequency ω/2π dependence of the proton spin‐lattice relaxation rate R in solid 1‐hydroxy‐2,4,6‐tri‐butylbenzene. The data is interpreted in terms of the rotational motion of the t‐butyl groups and their constituent methyl groups. Our data is much more extensive than a previous report [J. Yamauchi and C. A. McDowell, J. Chem. Phys. 75, 1051 (1981)] resulting in a revised dynamical model and considerably larger rotational barriers. Interesting thermal history effects are discussed

Clinical implications of the anisotropic analytical algorithm for IMRT treatment planning and verification

PURPOSE: To determine the implications of the use of the Anisotropic Analytical Algorithm(AAA) for the production and dosimetric verification of IMRT plans for treatments of the prostate, parotid, nasopharynx and lung. METHODS: 72 IMRT treatment plans produced using the Pencil Beam Convolution (PBC)algorithm were recalculated using the AAA and the dose distributions compared. 24 of the plans were delivered to inhomogeneous phantoms and verification measurements made using a pinpoint ionisation chamber. The agreement between the AAA and measurement was determined. RESULTS: Small differences were seen in the prostate plans, with the AAA predicting slightly lower minimum PTV doses. In the parotid plans, there were small increases in the lens and contralateral parotid doses while the nasopharyngeal plans revealed a reduction in the volume of the PTV covered by the 95% isodose (the V95%) when the AAA was used. Large changes were seen in the lung plans, the AAA predicting reductions in the minimum PTV dose and large reductions in the V95%. The AAA also predicted small increases in the mean dose to the normal lung and the V20. In the verification measurements, all AAA calculations were within 3% or 3.5mm distance to agreement of the measured doses. Conclusions: The AAA should be used in preference to the PBC algorithm for treatments involving low density tissue but this may necessitate re-evaluation of plan acceptability criteria. Improvements to the Multi-Resolution Dose Calculation algorithm used in the inverse planning are required to reduce the convergence error in the presence of lung tissue. There was excellent agreement between the AAA and verification measurements for all sites

AAPM medical physics practice guideline 3.b.: Levels of supervision for medical physicists in clinical training

The American Association of Physicists in Medicine (AAPM) is a nonprofit professional society whose primary purposes are to advance the science, education and professional practice of medical physics. The AAPM has more than 8,000 members and is the principal organization of medical physicists in the United States. The AAPM will periodically define new practice guidelines for medical physics practice to help advance the science of medical physics and to improve the quality of service to patients throughout the United States. Existing medical physics practice guidelines will be reviewed for the purpose of revision or renewal, as appropriate, on their fifth anniversary or sooner. Each medical physics practice guideline represents a policy statement by the AAPM, has undergone a thorough consensus process in which it has been subjected to extensive review, and requires the approval of the Professional Council. The medical physics practice guidelines recognize that the safe and effective use of diagnostic and therapeutic radiology requires specific training, skills, and techniques, as described in each document. Reproduction or modification of the published practice guidelines and technical standards by those entities not providing these services is not authorized. The following terms are used in the AAPM practice guidelines: (1) Must and Must Not: Used to indicate that adherence to the recommendation is considered necessary to conform to this practice guideline. (2) Should and Should Not: Used to indicate a prudent practice to which exceptions may occasionally be made in appropriate circumstances